Apparatus and system for transporting and positioning prefabricated modules in the construction of seagoing ships

ABSTRACT

There is provided a system including both a method and apparatus for use in the transport and positioning of prefabricated modules during the construction of seagoing ships. The system consists of a rotatable cradle for receiving port or starboard bound modules on their side. Rotation of the cradle into a dock positions and uprights the module for reception by a set of hydraulically operated transverse rail cars to traverse the dock between its port and starboard positions and having lift and descend mode functions incorporated as part of its internal structure. The transverse cars lift the module from the cradle and move it to the opposite side of the dock where it deposits the module on blocks by the descend or lowering function, then moves out of the way. A set of longitudinal rail mounted transport cars, tended by a power and control car moves under the deposited module, lifts it and transports it to either a second deposit zone for return to the cradle side of the dock for movement to the ship or transports the module to the ship at the side of the dock where the module was initially deposited. If the longitudinal transport cars deposit the module in the second deposit zone, it is then lifted, traversed across the dock to a third deposit zone by the transverse cars which are again removed and the longitudinal transport cars are again used to lift and transport the module to final position on that side of the ship. While transverse cars need only have forward, reverse, lift and descend functions, the longitudinal cars, which travel along the axis of the ship under construction, have forward, reverse, lift, descend, lateral movement, roll, pitch and yaw functions incorporated therein. These functions are powered and controlled by the attending power and control car. In the preferred embodiment, all systems are operated hydraulically.

Apr. s, 1975 United States Patent Futtrup et al.

l l APPARATUS AND SYSTEM FOR and apparatus for use in the transport andpositioning TRANSPORTING AND POSITIONING of prefabricated modules duringthe construction of PREFABRICATED MODULES IN THE Seagomg p CONSTRUCTIONOF SEAGOING SHIPS The system consists of a rotatable cradle forreceiving [75] Inventors: Harold A. Futtrup, Whittier; Oliver portStarboard bounii modules h JohnstoneDiamond Barboth of Rotation of thecradle Into a dock posmons and uprights the module for receptlon by aset of hydraulically operated transverse rail cars to traverse 1Assignees: Ralph M- Parsons C mpany, L s the dock between its port andstarboard positions and g t Calm; Mitsui p l g having lift and descendmode functions incorporated and Engineering p y as part of its internalstructure. Tokyo Japan; mares! to each The transverse cars lift themodule from the cradle [22] Filed: Jan. 24, 1972 and move it to theopposite side of the dock where it de osits the module on blocks b thedescend or Appl' 220306 lov ering function, then moves out (if the way.

A set of longitudinal rail mounted transport cars, 1t4/77 R3 ll4/65 R;105/57 R; tended by a power and control car moves under the 105/455?l/2l8 A deposited module, lifts it and transports it to either a In. C].

second deposit one fur return to the cradle side of i 1 Field Search114/77- 65 R; 61/67- 66; the dock for movement to the ship or transportsthe 2|4/l52? 105/57 R 455, module to the ship at the side of the dockwhere the 182 R module was initially deposited. If the longitudinaltransport cars deposit the module in the second References Cited depositzone, it is then lifted, traversed across the UNITED STATES PATENTS dockto a third deposit zone by the transverse cars 1.522.726 1/1925 105/190R which are again removed and the longitudinal 2.039.274 4/1936 Latshaw105/218 A an p ar are aga n d to lift an nsp the 2.545.956 3/1951 Julien105/182 R module to final position on that side of the ship.

............ 2.875.871 3/1959 Govan et =11. 105/902 and descendfunfmons' l9ngmdmal cars l' 2,907,283 10/1959 Murkestein et 105/1112 Rlong the constructtont 2,986,075 5/1961 105/33 have forward, reverselift desoohd. lateral move-monk 3,429,288 2/1969 Suit 114/65 0 1. p t han ya functions rp a d in. 3.703.153 11/1972 Mueda 114/77 R Thesefunctions are powered and controlled by the attending power and controlcar. In the preferred Primary Examiner-Trygve M. Blix embodiment, allsystems are operated hydraulically.

Assistant Exan1inerSherman D. Basinger Attorney. Agent, or FirmChristie,Parker & Hale Claims, 13 Drawing Figures [57] ABSTRACT There is provideda system including both a method la R'JEMEUAFR 81975 3,875,887

sum UlUF 11 PCTENTEUAPR 81s? SHEET CUDF 11 PATENTED APR 8 I975 SHEET C50F 11 PATENTEDAPR 8i975 SHEET CEUF 11 PATENTEUAPR 8l975 SHEEI L8 1F lwli APPARATUS AND SYSTEM FOR TRANSPORTING AND POSITIONING PREFABRICATEDMODULES IN THE CONSTRUCTION OF SEAGOING SHIPS BACKGROUND OF THEINVENTION With the construction of passenger ships virtually at astandstill, most shipbuilding operations today are concerned with theconstruction of cargo ships.

Because of the economics involved, cargo ships are ever growing in sizeto maximize the amount of cargo, such as fuel oil, which can betransported in a single trip. In the construction of such ships, the bowand stem sections are the most time consuming to construct. The moduleswhich connect the bow and stem. and which become progressively, the portand star board sections ofa ship hull, are fairly easy to fabricate.

Their fabrication within the dock however is always hampered by changingweather conditions often involving lost time. It has therefore beenfound that the most economical way to rapidly construct a tanker is toprefabricate the port and starboard modules at a work center protectedfrom changing climatic conditions. These modules are of a sizecomparable to an 8 story building and weigh as much as 1,500 tons ormore. This permits full time utilization of workers assigned toconstruct the port and starboard modules for the ship or tanker. Inaddition, it has been found most economical to construct the modules ontheir side.

The problem then arises of transporting the modules from the point offabrication to dock-side, to position them within the dock and alignthem with the bow or stem of the ship, or to modules which have beenalready affixed to the bow or stem.

The problem of transporting a module to dock-side has been resolved.

SUMMARY OF THE INVENTION The present invention is concerned with asystem for receiving a prefabricated module on its side at dockside,positioning it upright within the dock and moving the module to thelocation where it is to be joined to either the port or starboard sideof a ship under construction and apparatus employed in this system.

The method, in general, consists of positioning a module on its sideonto a rotary positioning fixture. By rotation of a portion of thefixture, the module is lowered into the dock and simultaneously placedin an upright position where construction of the ship is under way.

The module is then lifted from the rotary positioning fixture by a setof synchronized rail mounted transverse cars which pass between port andstarboard sides of the dock. The cars transport the module from therotary positioning fixture to a predisposed location aligned withlongitudinal tracks on the opposed side of the dock and deposit themodule on blocks.

A set of longitudinally oriented rail mounted transport cars with anattending power and control car are brought under the deposited moduleand by built in lift and lowering functions, lift the module from theblocks and move it along one side of the dock forjoining to the ship orto a second point of drop where the longitudinally oriented cars depositthe module on blocks and move out of position.

The module is then picked up by a second set of traversing cars andreturned to the side of the dock where the rotary positioning fixture islocated and deposit the module on blocks and move out of the way.

A companion set of transport cars, with their attending power andcontrol car, then pick up the module and move it along a companion railsystem for joining to the opposed side of the ship under construction.

In this system, it is preferred that the rotary positioning fixture andthe traversing and longitudinal transport cars be hydraulicallyoperated, although other mechanical and electrical means may beemployed.

The apparatus associated with the operation, preferably, consists of arotary positioning fixture which operates in cooperation with two setsof transverse cars, and two sets of longitudinal transport cars withtheir attending control power and control cars. However, it is feasibleto operate with one set of each type of car simply by shifting carsbetween rails by available cranes.

As a minimum, the rail mounted transversing cars have the capability ofmoving in a forward and reverse direction, lifting a module from thecradle of the rotary positioning fixture or blocks and lowering a moduleonto blocks.

Each set of rail mounted longitudinal transport cars having an attendingcontrol power car to operate them in synchronization have forward,reverse, lift lowering functions which make them useful as transversecars, and the capacity to impart pitch, roll and yaw to a carried moduleto accurately align the carried module with that portion of a ship whichhas already been assembled.

THE DRAWINGS FIG. I is a schematic illustration of the overall moduletransport system employed in the practice of this invention.

FIG. 2 is a typical layout for a track system for the module transportsystem showing the inter-relationship of both the traversing andlongitudinal module moving cars.

FIG. 3 is atop view of a portion of one of the longitudinal moving carswhich may be used also as traversing car as such, or with minordelineations of apparatus.

FIG. 4 is a side view of the longitudinal car shown in FIG. 3.

FIG. 5 is a detail drawing of the suspension system used for all wheelsfor both the transverse and longitudinal cars whether powered or not.

FIG. 6 is a detail top view of the drive system for both thelongitudinal transport and transverse cars.

FIG. 7 is a rear view of the drive system shown in FIG. 6.

FIG. 8 is a schematic of the drive mechanism shown in FIGS. 6 and 7.

FIG. 9 is a diagramatic plan view of the hydraulic control system of apair of longitudinal transport cars.

FIG. I0 is a schematic diagram of the hydraulic system of any onetransport car.

FIG. 11 is a schematic wiring diagram relay control system of any onetransport car.

FIGS. 12 and 13 combined are a schematic wiring diagram of the hydraulicvalve control circuit of any one transport car.

DESCRIPTION According to the present invention, there is provided amethod and apparatus for use in transporting port and starboard modulesfor a seagoing ship, typically a cargo ship. prefabricated on theirside. from dock-side into the dock in an upright position and onward forexact positioning with the ships hull under construction.

With reference now to FIGS. 1 and 2, there is provided a general outlineof the total module transport system.

With reference first to FIG. 1, there is provided as part of the generaldock-side facility, a conveyor system for bringing modules 12 on theirside to dockside for insertion into, and positioning them in properalignment with ships under construction in construction dock 14.Associated with a typical ship building operation, there are providedtrack mounted cranes 16 which are used both in the construction of thevessel and in the assembling and disassembling of the module transportsystem of this invention. These cranes are however, at present,incapable of handling the weight of a prefabricated module. There isalso shown for reference purposes, tanker bow l8, constructed or underconstruction and a portion of the stern section 20, in which there isillustrated a number of modules already secured in place by a weldingoperation.

In accordance with the present invention, the transport system isparticularly adapted for the movement of port and starboard modules 22and 24, with the construction of the intermediate sections 26 beingcarried out in a conventional manner. The systme, however, by theaddition of an additional set of tracks may be used for installation ofcenter sections 26 when they are adaptable to prefabrication outside theconstruction dock.

In the system illustrated, module transport is shown taking place fromthe starboard side of the ship. It will be appreciated, however, thatthe reverse of the operation is equally feasible to permit modulemovement from port side. However, for ease in description, the operationof the system will be described in terms ofa starboard positionedoperation.

The initial point of the operation is to bring a prefabricated moduleunit 12, shown in the drawing for ultimate positioning along thestarboard side of the vessel to rotary positioning fixture 28. It willbe appreciated that if the prefabricated module 12 were destined forport positioning, it would be delivered in a 180 position relative tothe position illustrated.

There is shown on the rotary position fixture 28 a module 24 destinedfor alignment along the starboard side of the vessel. Rotary positioningfixture 28 consists of support structure 30 having at the upper endthereof a pair of parallel rails 32, each of which contain a pluralityof teeth 34 intermeshed with the teeth of a pair of rotary quadrantgears 35 secured to block 36 which is in turn secured by arms 38 tocradle 40 having module support arms 42 at one end and counter balancedat the opposed end. Both cradle 40 and support structure 30 are readilydismantleable for removal from the dock when the last section(s) of theship are installed in the zone initially occupied by them.

By cooperative actuation of forward and aft hydraulic cylinders 44 and46 their mates being on the opposed parallel rail 32 of the supportstructure 30, quadrant gears 35 are rotated which causes cradle 40 tomove forward and simultaneously rotate to position upon termination ofrotation module 24 in an upright position against a stop (not shown) ata level above the tracks to permit, with reference to FIG. 2, transversesynchronized cars 48 and 50 which have at least the mode capabilities ofmoving forward, reverse, upwards and downwards to engage in a loweredposition the underside of a cradle held module 24.

There is also provided as part of the system, cradle wells 52 to receivethe cradle of rotary positioning fixture 28.

Associated with rail mounted transverse cars 48 and 50 and 49 and 51which are respectively interconnected by an umbilical cords 54 and 55 topermit synchronous operation of both cars by a control center on one(not shown), with one car of each set being connected to a dock-sidesource of power (not shown). Operation of a pair is generally carriedout by an operator walking with the cars. The cars are moved along theirrespective track systems 56 and 58 between the cradle of rotarypositioning fixture 28 to deposittransfer area 60.

The transverse cars 48 and 50 (as indicated) have a lift mode ofsufficient elevational capacity to lift a module 24 from the rotatedcradle. The transverse cars 48 and 50 then transport the module to area60, in which are located platforms 62 having a required number ofelevated cross over plates 64, which exist at the intersections of alltracks.

The tracks are in both the transverse and longitudinal direction and arespaced from cross over plates 64 to account for thermal expansion. Theheight of cross over plates 64 is sufficient such that the flangedportions of the wheels of both the transverse cars 48 and 50, and 49 and51, as well as longitudinal transport cars 66 and 68 may ride over themin a manner such that the rail tread portions of the wheels of each carwill engage a rail after passage of the wheels over cross over plates64.

As shown in FIG. 2, there is provided a set of three longitudinal railsystems 700, 72a and 74a and 70b, 72b and 74b. This, as illustrated inFIG. 2 allows the longitudinal cars to be spaced depending on the widthof the module to be transported for interconnection with the ship. Asillustrated in FIG. 2, port side longitudinal cars 66 and 68 are onouter tracks 70a and 74a for transport of a large module whereascompanion starboard side longitudinal cars 66 and 68 are on tracks 72band 74b for transport of a more narrow module so that the center ofgravity of a module shall be between the longitudinal cars.

Returning now to the operation, transverse cars 48 and 50 enter underthe module deposited in an upright position by the rotary positioningfixture 28 and raise.

the module by hydraulic action from the cradle. It is then transportedacross tracks 56 and 58 to zone and lowered by transverse cars 48 and 50in a synchronous manner into pre-set blocks (not shown). The platens ofthe traversing cars are then lowered and the cars removed to a neutralzone as shown in FIG. 2 or returned to pick up another module.

Longitudinal cars 66 and 68 with their attending power car 76 with theirplatens lowered below the level of the deposited module pass under themodule and lift it from its blocks.

With reference to FIG. 1 where the module is to be transported to theport side of the ship, it is lifted from the blocks, carried by a set oflongitudinal transport cars 66 and 68 along any preselected pair oftracks.

Where instead, the module is destined for positioning along thestarboard side of the ship under construction,

transport cars 66 and 68 only transport the module to the opposed end ofzone 60 where it is again deposited on prepositioned blocks, the platensof cars 66 and 68 then being lowered from the deposited module and thecars moved out of place. Transverse cars 49 and 51 generally operated inthe same manner as cars 48 and 50 interconnected by umbilical cord 55then come into play and are driven along tracks 57 and 59, with theirplatens in a down mode position, and pass under the deposited module,lift the module from its blocks and transport the module along tracks 57and 59 to area 78 where it is again deposited on a pair of predepositedblocks (not shown) and cars 49 and S1 moved out of place.

Starboard side longitudinal cars 66 and 68 as powered by control andpower car 76 then move under the module, lift it and transport it alongthe starboard side of the dock as shown in FIG. 2 to the stern sectionof the ship.

It will be appreciated that a companion transfer system may bepositioned on the bow side of tracks 56 and 58 for carrying out the sameoperation with respect to the starboard bow section of the ship.

When the cradle is positioned in the starboard side of the dock acompanion set of longitudinal cars may be employed on the starboard bowdirected tracks corresponding to tracks 70b, 72b and 74b for operationsconnected with the starboard construction of the ship.

To that extent, once the utility of the longitudinal cars associatedwith the construction of the starboard side of the stern portion of thetanker has ended, they may be moved by cranes 16 to the bow side of thero tary positioning fixture to position modules against the starboardside of the bow portion of the ship.

Before attending to the flexible utility of transport cars 66 and 68whose operation is modulated by attending power and control car 76, somedetail of their construction and subconstruction be dealt with.

With reference now to FIGS. 3 and 4, there will be described generalelements of the transverse and longitudinal transport cars withparticular emphasis being directed to the elements ofa longitudinaltransport car as it includes all the modes of operation but is morecomplex than a transverse car.

Referencing it to transport car 68 or its companion 66 of HO. 2, itconsists in general ofa rigid chassis 80 consisting of longitudinalstructural beams 82 and a plurality of transverse support beams 84.These support a platen 68 consisting of frame 87 carrying a plurality ofspaced module support units 88. Platen 86 is supported on and spacedfrom chassis 80 by slide bearing spacers 90 between beams 82 and framev87.

A plurality of port and starboard oriented hydraulic cylinders 92 arepositioned at the forward and aft ends of each longitudinal transportcar and connect to beams 84 and frame 87 of platen 86.

When hydraulic cylinders 92 are actuated. the platen 86 is movedlaterally on the slide bearing surfaces 90. If the forward cylinder 92ais actuated in one direction and the aft cylinder 92b is actuated in theopposite direction, the platen is rotated;

There is also contained on chassis 80 hydraulic power system 98, theenergy to which is supplied from attending control car 76 (not shown)and the necessary hydraulic control valves (not shown) and hydraulicpiping (not shown). The hydraulic valves are electrically controlledfrom the control car 76.

The attending control car 76 consists primarily of a rail mounted dieselgenerator and a control unit for a set of longitudinal cars. Inoperation, the attending car 76 provides power to a set of longitudinalcars but is not self driven, rather it is carried along by thelongitudinal transport car to which it is connected.

The cars, whether transverse or longitudinal trans port in nature,generally have 12 sets of axle connected wheels adapted to engage atrack in the tread sections thereof and roll over a rail crossover plateon machined flanges. For the operation approximately normally onethirdof the total wheel units are powered by hydraulic motors secured tobeams 84. As illustrated in FIG. 3, three such motors are shown, afourth being hidden by the platen 86.

Although the driven wheels may be positioned at any point along thelength of the car, they are preferably positioned at the central portionof the car with two motors, where 12 wheel units are employed, beingpositioned on each side of the center line (G) of the car. Thesuspension system for each set of wheels whether driven or not isindicated by 102 in FIG. 4.

In considering a transverse car, since only upward and downwardmovements are required, in addition to forward and reverse, and lateralmovement unnecessary, hydraulic cylinders 92a and 92b, as well as slidebearings 90, may be eliminated and platen 86 secured directly to chassis80 of the car. In the alternative, the frame 87 of platen 86 may beeliminated and support members 88 connected directly to chassis 88 ofthe transverse cars.

While this will minimize construction costs for the transverse cars, itis possible, however, that all cars have identity of construction in sofar as the car elements are concerned in order that they may be utilizedas both transverse and longitudinal cars.

With reference now to FIGS. 4 and 5 and particularly FIG. 5, there isshown the detail of the suspension sys tem provided for each wheel ofatransverse or longitudinal car whether driven or merely a rollingsupport wheel.

Suspension system 102 is connected to longitudinal beam 82 of chassisstructure 80 by support structure 104, shown in FIG. 7 and secured to itby torsion bar 106 which is keyed to member I08 secured to suspensionframe 110. There is also secured to frame 110 parallel to torsion bar106 the axle of wheel 112 which engages track 114.

The opposed end of suspension frame 110 is connected to hydrauliccylinder 116 which is in turn pivotally connected to frame 110 andtransverse beam 84.

A companion structure appears on the reverse side of the car with itstrack supported wheel interconnected to wheel 112 by a common axle.

In this suspension system, torsion bar 106 tends to hold chassis 80level while at the same time permitting, by torsional deflection, onewheel 112 to be higher or lower than its companion axle coupled wheel byan amount of elevation difference to be expected in the setting of rails114. While the resulting wheel loads will be slightly different due tothe resulting torque in torsion bar 106, the loads on the hydrauliccylinders I16 will remain constant since they are hydraulicallyinterconnected. The suspension system employed for each pair of axlewheels 112 plays an important part in the various mode functions forboth the transverse and longitudinal cars.

As a minimum, all hydraulic cylinders 116 may be employed in conjunctionto raise or lower the platform 80. and other members on it, of each carto receive or deposit a module at a desired position along the moduletransport system.

This is accomplished, where a raised function is, for instance. requiredby forcing fluid into hydraulic cylinders 116 associated with each pairof rail engaged wheeis 112. Since the tracks 114 are firmly affixed tothe floor of the dock. the only member which may move is frame 80 of thecar causing rising of the car relative to the wheel by pivoting ofsuspension frames 110. In a reverse function, lowering of the carrelative to the wheels is achieved by uniformly exhausting hydrauliccylinders 116. The position of the wheels which engage the rails.however, remains unchanged. Therefore pivot occurs about the axle of thewheels. Any tendency for frame 80 to rise at one side more than theother is opposed by torsion bar 106.

With reference now to FIGS. 6, 7 and 8 there is described the drivemechanism employed for any one of the driven rail engaging pairs ofwheels on either the longitudinal or transverse cars.

With reference first to FIG. 6, there is shown the top view of themechanism involved in the raising and lowering functions as well as theforward and reverse mode of operation of one of the driven rail engagingwheel pairs which differs from a traveling axle connected wheel paironly by the drive mechanism employed.

There is provided as part of chassis 80, longitudinal structural members82 and transverse beams 84, a companion pair of hydraulic cylinders 116attached in pivotal relation to longitudinal structural members 82 andsuspension frames 110.

As indicated. the principal mode of function to be described is thatassociated with driving a car in either a forward or reverse directionemploying driven wheels.

As part of the system, there is secured to beam 84 a reversiblehydraulically driven motor 100. Through a reduction gear box 101, itsupplies by a chain drive, power from sprocket 120 to sprocket 122secured to annular drive shaft 124 which surrounds the torsion bar 106.The power is in turn transmitted to sprocket 126 also secured to annulardrive shaft 124 and transmitted in turn by a chain drive to sprocket 128on axle 130 connecting a pair of wheels 112.

With reference now to FIG. 7 which is the rear view of FIG. 6 and withadditional reference to FIGS. 3, 4 and 5, there is shown all the commonmembers. Here again, hydraulically driven motor 100 through gear box 101drives sprocket 120 connected by chain drive to sprocket 122 whichthrough annular drive shaft 124 transmits power to sprocket 126 which,with reference to FIG. 6, transmits by a chain drive. power to sprocket128, attached to axle 130 to propel axle coupled wheels 112 in either aforward or reverse direction. By means of support structure 104, theentire system is pivoted about torsion bar 106 to maintain the point ofpivot during lift and descend modes about the axle 130 connecting wheelpairs 112 in order that axle connected wheels 112 may be maintaining ina stationary position while chassis 80 may be raised and loweredrelative to axle connected wheels 112 by coaction of hydraulic cylinders116 in cooperation with torsion bar 106.

With reference now to FIG. 8, there is provided a schematicrepresentation of the drive mechanism employed. To rigid chassis 80consisting of longitudinal beams 82 and transverse beams 84, there issecured thereto hydraulically driven motor connected to a reduction gearbox 101. Power is transmitted to sprocket connected by a chain drive tosprocket 122 secured to annular drive shaft 124 which rotates abouttorsion bar 106. This power is then transmitted through annular driveshaft 124 to the companion sprocket 126 (not shown) and by a chain driveto sprocket 128 attached to axle 130 interconnecting wheels 112maintained in contact with rails 114.

This drive mechanism permits the use of the hydraulic system to raiseand lower the chassis 80 relative to wheels 112 without changing thecontact force between wheels 112 and track 114.

As to the multiplicity of paired wheels 112, the only difference betweenthe driven wheels and rolling wheels is that the motor drive mechanismsare eliminated. Apart from them, every element shown in FIGS. 5 to 7 ispresent with the wheels coupled to torsion bar 106 by frame members 110which are rotatably con nected to axle 130 of wheels 112 and which arein turn pivotably connected to hydraulic cylinders 116 attached totransverse beam 84 of chassis 80 which again permits raising andlowering of chassis 80 relative to wheels I12 supported on rails 114.

Considering now FIGS. 2 through 8, there will be described the severalfunctional modes available to each of the rail engaged longitudinal cars66 and 68 as controlled by attending cars 76.

Traverse movement of a contained module on a set of cars has alreadybeen described with reference to, in particular, FIGS. 3 and 4.

Forward and reverse operation of any car alone or in conjunction withanother is simply accomplished by employing the drive mechanism of thedriven wheels of any one of or set of the longitudinal transport ortransversing cars.

With respect to longitudinal transport cars 66 and 68, control is byattending control and power car 76 which is connected directly to one ofthe longitudinal cars which is connected to the other by a for or aftumbilical cord 132. This permits entry under and removal from underneathmodules under all patterns of blocking.

As indicated with respect to transversing cars, operated as a pair, theminimum mode functions are forward and reverse operations as well asraising and lowering ofchassis 80 of the cars through action ofhydraulic cylinders 116 associated with the suspension mechanismillustrated in FIG. 5. A set of transverse normally cars operate inunison to maintain chassis 80 level with,

respect to their longitudinal and transverse axis.

Longitudinal transport cars operating as a pair are adaptive to movecomplex modes of operation.

There is, of course. forward and reverse, as well as raising andlowering of chassis 80 of each car alone or in conjunction with theother by means of hydraulic cylinders 116 and drive mechanism as hasbeen described above and the sideward motion of the platen by hydrauliccylinders 92a and 92b.

For proper alignment of a transported module with a companion modulealready attached to either the bow or stem ofa ship under construction,there are incorporated additional functions.

One involves roll. This involves rotation of the module supported by apair of companion cars 66 and 68 about the longitudinal axis. This isachieved by raising or lowering the chassis 80 of one of the carsrelative to the other. The slight angular rotation of the platen 86 andchassis 80 of each car relative to the longitudinal axes of the carsthat occurs during this motion, while the axles 130 remain parallel tothe dock floor, causes a small relative extension of the hydrauliccylinders 116 on the rising side and a retraction of those on thelowering side of each car and there is a slight twist of the torsionbars 106. The differential motion of the opposed hydraulic cylinders ofa pair is accommodated by exchange of hydraulic fluid through theircommon manifold. The torsion bar accepts the twist elastically andreturns to its original shape after the load is removed.

The next function available is pitch. This involves pivoting of rigidchassis 80 about a transverse axis relative to tracks by hydraulicforces introduced through hydraulic cylinders 116. The cylinders 116 areinterconnected in two groups, the groups, with reference to FIG. 3,being all hydraulic cylinders 116 associated with all wheels forward ofcenter line (C) and all hydraulic cylinders of all wheels aft of thecenter line (C).

If an upward pitch is desired, hydraulic fluid is pumped into all of thehydraulic cylinders 116 connected to the suspension systems of allwheels forward of the center line (C) of the transport cars 66 and 68.Each suspension system associated with each pair of whcels will raise inthe amount required to maintain the platen in intimate contact with themodule.

In the aft portion of the cars, there is an interchange of hydraulicfluid from the forward half of the aft group of cylinders 116 to therear half of the group 112. Again, in proportion to the degree ofangular rotation imposed, there will be extension or retraction of alltransverse pairs of cylinders 116 as required to maintain the platen inintimate contact with the module. In this mode of operation pivot willbe, in general, about the center of the rear group of cylinders.

It will be appreciated that the reverse will occur if pitch in theopposed direction is desired and that similar results could be achievedby raising or lowering the rear group of cylinders [16 or by actuatingthe forward and rear groups oppositely and simultaneously.

The next function is yaw which produces a rotation of the module about avertical axis. With particular ref erence to FlGS. 2, 3 and 4, forclockwise yaw employing port side longitudinal cars 66 and 68, this isinduced in part, by activation of hydraulic cylinders 92a and 92b.Cylinders 92b in the aft portion of both cars can be activated to movethe platen toward the port side and activation of the hydrauliccylinders 92a in the forward portion of each car can be activated tomove the platen toward the starboard side. Simultaneously, longitudinalcar 66 is driven aft while longitudinal car 68 is driven forward. Theclockwise rotation of the platens produces the clockwise rotation of themodule while the aft motion of car 66 and the forward motion of car 68produce the forward and aft motions of the port and starboard sides ofthe module which occur as a natural result of the clockwise rotation.

It will be appreciated that if the actuation of hydraulic cylinders 92aand 92b and the longitudinal drives of cars 66 and 68 are all reversedfrom the directions indicated above that a counter clockwise motion ofthe module will result.

It will further be appreciated, however, that the degree of yaw willnormally be minimal as the major alignment of the module on the set oflongitudinal cars is established and maintained throughout the assembly,rotation and transport of the module.

By imparting the several degrees of motion, each in the proper amount, amodule to be connected to a vessel may be accurately aligned with apreviously positioned module within the degree of precision required bythe industry and that it can then be blocked in that positionpreparatory to welding to its neighbors.

The longitudinal cars may then be relaxed to their normal position.frame and platen 86 thereby lowered, and the companion pair of carsremoved out of position for reception of another module.

Although the operation of the entire system has been described as beinghydraulically powered, there are provided electrical control systems forthe various hydraulic power systems. It will be appreciated thatpneumatic or hydraulic control systems could be employed in lieu of theelectrical. The electrical control system facilitates engagement anddisengagement of the sets of cars and facilitates the control of sets ofcars by one operator from one control console. It will be furtherappreciated that both types of cars can be operated either singly or insets.

in addition, while the system has been described as operatedhydraulically, there may be employed any other operative means such asDC driven motors with screw drive to supplant hydraulic cylinders aswell as induction AC motors again associated with screw drives toachieve the various functions accomplished hydraulically. Some specialprovision would have to be made to achieve the synchronization and loadequalization that is essentially automatic in the hydraulic sys tems.Electrical motor drives may also be used to propel the cars.

While it is preferred that the driven wheels occupy the central portionof each car, it will also be appreciated that each wheel may be equippedwith a drive mechanism or that drive mechanisms may be associated withwheels other than those centralized with respect to the center line ofeach car.

Further, more than one-third of the available wheel pairs may be drivenor less than one-third of the available wheel pairs of each car may bedriven depending upon the traction and power requirements for each caremployed.

While it is preferred, in the system described, that a set of carsconsist of two cars, it will be appreciated that any number of cars canbe included in a set, according to the load and space requirements.

The transport system of this invention is capable of accuratelypositioning modules during the construction of ships having a deadweight tonnage ranging from about 200,000 tons to about 580,000 tons ormore. The modules employed in their construction will generally range inweight from about 675 tons to about l,500 tons.

To accomplish this task, both the transverse and transport cars have anoverall average length of about 70 feet and an average width of about6.5 feet.

Car dimensions, however, are subject to change de pending upon the sizeand weight of a module to be transported within a dock during ashipbuilding operation.

Referring to FIG. 9, there is shown the basic power control system ofthe longitudinal cars 66 and 68. Each car includes a pair of hydraulicpumps a and 140b, each driven by an electric motor 142. Electric powerand control lines extend from the tender car 76, which has adiesel-powered generator 143 and a central control panel 145. The planview of the car 66 in FIG. 9 shows diagrammatically 24 hydraulic lifingcylinders 116 arranged with 12 lifting cylinders 116a forward of thecenterline of the car and I2 lifting cylinders 11612 aft of thecenterline. Also for control purposes, the lateral cylinders 92 arearranged in two groups, a forward group 92a of four and an aft group92!) of four. The position of the four load motors 100 is also shown.While the lift cylinders 116 have been indicated in relation to theinboard car 66 and the lateral control cylinders and the drive motorshave been shown in the outboard car 68 in FIG 9, it will be understoodthat both cars include all of the lift cylinders. lateral controlcylinders and drive motors arranged as shown for each car.

Referring to FIG. 10, the hydraulic control system for one longitudinalcar is shown diagrammatically. The two pumps, designated at 140a and1401), pump hydraulic fluid from a common reservoir 146. Bypass valves148a and 148b return fluid from the outlet side of the pumps directly tothe reservoir until the control system requires hydraulic power to bedelivered to any of the motors and/or control cylinders, at which timethe valves 148 are closed. The fluid from the pump 1400 is supplied by ahigh-pressure hydraulic line to each of the three control valves 150,152,-and 154. The output of the pump l40b is similarly supplied by ahighpressure hydraulic line to two other control valves 156 and 158, andalso to the control valve 154. Each of the control valves 150 158 has alowpressure return line going back to the reservoir 146.

Each of the control valves 150 158 has three control positions. Theintermediate or neutral position, shown in FIG. 10, is an OFF positionin which fluid does not flow through the control valve. The controlvalves, which are each solenoid-actuated by a pair of solenoids. such asindicated at 1500 and 15011, 152a and 152b, 1540 and 154b, 156a and156b, and 158a and 158b, can be moved in either direction from theintermediate position, so as to direct fluid through the valve to oneoutlet port or the other outlet port of the control valve, as shown bythe arrows in FIG. 10.

The control valve 150 is used to control the flow of fluid to the twelveforward lift cylinders I160. The l2 cylinders are connected in paralledacross a pair of hydraulic lines extending back to the two outlet portsof the control valve 150. Thus when the control valve 150 is actuated tomove it to a RAISE position by solenoid 150a, fluid pressure is appliedto one side of all of the l2 cylinders to cause movement of the forwardend of the car frame in a lifting direction. When the control valve 150is moved to the LOWER" position by solenoid 150b, the hydraulic pressureis applied to the other side of all twelve cylinders 116a, causing a netmovement of the forward end of the car frame in the lowering direction.By connecting the cylinders 1160 in parallel. the fluid pressureequalizes among the cylinders so that if a greater external force isapplied to some of the cylinders providing a net increase in fluidpressure, fluid will be forced into the remaining cylinders until theload is equalized. This permits the unequal movement of the liftcylinders when a pitch movement is applied to the car frame by actuatingthe forward lift cylinders 1160 but not the aft cylinders [16b or topermit adjustment of the wheels in passing over high points on therails.

Similarly the control valve 156 controls the twelve aft lift cylinders116b, the twelve cylinders being connected in parallel across thealternate outlet ports of the control valve 156, permitting the controlvalve 156 to provide fluid under pressure selectively to either side ofall of the aft lift cylinders to produce a net lowering or raisingmovement of the aft portion of the longitudinal car.

The control valve 152 similarly provides fluid under pressure to eitherside of the four forward lateral cylinders 920 connected in parallel. Bymoving the control valve either to a starboard" or port" position bymeans of solenoids 152a or 152b, the fluid under pressure is applied tothe lateral cylinders to produce a net movement either in the starboarddirection or the port direction. Again, by connecting the cylinders inparallel, the pressure is equalized and the cylinders adjustautomatically to equalize the load on each cylinder.

The control valve 158 by means of solenoids 158a and 15% similarlycontrols the four aft lateral cylinders 92b.

The control valve 154 by means of solenoids 154a and l54b controls thedirection of flow of hydraulic fluid through the drive motors 100, whichare also connected in parallel, the control valve 154 having a forward"position and an aft position in which the drive motors operaterespectively to drive the car in a forward direction or in an aftdirection.

A lift leveler control is provided by a solenoidoperated valve 155 whichbypasses the output of the pumps a and 14% through check valves 157 and159 and through a pressure-relief valve 159 back to the reservoir 146.The valve 159 is set to open when the pressure reaches a predeterminedlevel, for example 500 psi, so as to limit the pressure of the fluid inthe system whenever the valve 155 is open. This arrangement is used wheninitially raising' the platens of the two cars against the module. Theplatens, under limited pressure, are pressed against the module so as totake up any lost motion without applying sufficient force to actuallylift the module off its supports. The leveler control is then turned offand full pressure applied to all the lift cylinders to raise the module.The initial leveling action insures that the load is equally distributedto all four groups of lifting cylinders 116.

Operation of the control valves 158 to properly position a module isshown by the schematic wiring diagrams of FIGS. 11 and 12. The controlcircuit controls and coordinates the operation of both the inboard carand the outboard car which together support and posi-. tion a singleship module 24. FIGS. 11 and 12 show two electrical circuits, one foroperating a series of relays in response to manually controlledswitches, and the second circuit for controlling the hydraulic controlvalves 150 158 in both the inboard and outboard longitudinal cars inresponse to the relays in the first circuit.

Considering first the relay control circuit, the relays are driven froma relatively low voltage, for example 50 volts, derived from thesecondary of a transformer 160, the primary of which is connected to theelectrical power source provided by the generator 143. All operationscan be controlled from either a remote control panel or a local controlpanel which provide duplicate control push buttons for controlling thevarious positioning movements which can be imparted to the module by theinboard and outboard longitudinal cars. In

the drawing, all relay contacts operated by the same relay bear the samereference number followed by a letter. Normally closed relay contactsare represented by a pair of parallel lines with a slant line throughthem. thus Normally open relay contacts are represented by a pair ofparallel lines without the slant line. thus -l Forward and aft movementof the module is controlled by a group of push-button switches,including local and remote STOP switches. local and remote FWD switches.local and remote AFT switches, local and remote .IOG FWD switches andlocal and remote .lOG AFT switches. The STOP switches have normallyclosed contacts connected in series circuit with normally closedcontacts of the .lOG FWD switches, the normally open relay contacts162a, normally closed relay contacts 164b, and the coil of relay 162across the (J-volt voltage source. Normally open contacts operated byFWD push-button switches are connected in parallel across the contacts1620: so that pushing either of the FWD switches completes a circuitenergizing the relay 162 to close the contacts 1620. The relay 162 thenremains energized until one of the STOP switches is actuated, breakingthe circuit through the relay 162. The relay 162 is also energized bydepressing either of the JOG FWD switches to close normally opencontacts to complete a circuit through the relay coil 162 that bypassesthe contacts 162a. Thus when a .lOG FWD switch is released, the relay162 is immediately deenergized without operating the STOP switches.

The two STOP switches are also series connected through normally closedcontacts operated by the JOB AFT switches, the normally open contacts164a, normally closed contacts 162b, and the coil of a relay 164. TheAFT switches have normally open contacts connected in parallel acrossthe contacts 1640 so that depressing either AFT switch energizes therelay coil 164. The JOG AFT switches also include normally open contactswhich, when closed, complete a circuit through the relay coil 164, butbypass the contacts [640 so that the relay is de-energized when the JOGAFT switches are released.

It should be noted that the normally closed contacts 164]; and 162bprovide an interlock arrangement so that both the forward and aft drivescannot be operated at the same time by someone attempting to close boththe FWD switch and the AFT switch at the same time.

The relays 162 and 164, when activated, operate the hydraulic controlvalve 154 to operate the hydraulic drive motors 100 in direction to movethe longitudinal cars in a forward or in an aft direction. To this end,solenoids of the control valves are connected by particularrelay-operated contacts in a second circuit shown in FIG. 12. All relaycontacts have the same reference numberal as the associated relay in therelay circuit of FIG. 11 with an added letter for identification. Therelay 162 has normally open contacts 1626 which connect the solenoid154a associated with the control valve 154 of the outboard car acrossthe voltage source. Thus when the relay 162 is energized, closing thecontacts 1626, the solenoid 154a moves the control valve 154 to aposition to pass hydraulic fluid to the drive motors in a direction tomove the outboard car 68 in a forward direction. Similarly normally opencontacts 162d connect the solenoid 1540 of the control valve 154 in theinboard longitudinal car 66 to the forward position when the relay coil162 is energized.

To drive the two cars in the aft direction. normally open contacts 164(and 164d energize the reverse solenoids l54b of the control valves 154in both the outboard and inboard longitudinal cars.

To raise and lower the module, the control circuit of FIG. 11 includes apair of relays 166 and 168. The relay 166 is activated by either a localor remote UP pushbutton switch, the normally open contacts of the UPswitches being connected in parallel across the nor mally open contacts166(' operated by the relay 166. Similarly the relay 168 is energized byoperating either one of a pair of DOWN push-button switches havingnormally open contacts connected in parallel across the normally opencontacts 168C operated by the relay 168.

The relay 166 when energized closes normally open contacts 166C to lockthe relay 166 while relay 168 when energized closes normally opencontactss 168C to lock the relay 168. Either relay is released by eitherone of two STOP switches having normally closed contacts connected inseries with both relays.

Referring to FIG. 12, the relay 166 operates normally open contacts 166dto complete a circuit through the solenoid 1560 operating the controlvalve 156 to raise the aft section of the outboard car. A pair ofnormally open contacts 1660 operated by the relay 166 at the same timecomplete a circuit through the solenoid 1560 of the control valve 156 inthe inboard car for raising the aft section on the inboard car. Theoutboard car forward section is raised by closing normally open contacts166f, operating energizing solenoid 1500 to operate valve 150. Theinboard car forward section is also raised by closing contacts 166g.

Similarly, the relay 168 closes normally open contacts 168d and 168a tooperate the solenoids 15619 associated with the valves 156 for loweringthe aft section of the outboard and inboard cars. Closing of normallyopen contacts 168f and 168g operates solenoids 15% for lowering theforward sections of the outboard and inboard cars.

The roll control includes a pair of relays 170 and 172. The relay 170 isenergized by pushing either one of a pair of ROLL STBD switches to closenormally open contacts. Normally closed contacts 172a are connected in aseries with the relay 170, while normally closed contacts 170a areconnected in series with the relay 172 to provide an interlock toprevent both the starboard and port roll to be initiated at the sametime. The relay 172 is energized by closing one of two ROLL PORTpush-button switches to actuate a pair of normally open contacts.

As shown in FIG. 12, relays 170 and 172 cause the outboard car aftsection to be raised or lowered by operating respectively normally opencontacts 170b connected in parallel with the normally open 166d contactsand by the normally open contacts 172b connected in parallel with thenormally open contacts 168d. Also the outboard car forward section israised and lowered at the same time by control valve by normally opencontacts C and 1726 respectively. Thus it will be seen that a rollstarboard is accomplished by raising the aft and forward sections of theoutboard longitudinal car together while the aft and forward sections ofthe inboard car remain at the same level.

Pitch is controlled by a pair of relays 174 and 176 (see FIG. 11).Closing the normally open contacts of either one of the PITCH AFTswitches completes a circuit through the relay 174 and the normallyclosed contacts 176a. Closing either one of the PITCH FWD switchessimilarly energizes the relay 176 through the normally closed contacts174a. The contacts 174a and 1760 provide an interlock between the tworelays to prevent both relays from being energized at the same time.

To effect a pitch aft. as shown in FIG. 12, the relay 174 closesnormally open contacts 174]) and 1740. These contacts, when closed,complete a circuit through the solenoids 150a associated with thecontrol valves 150 to raise the forward section of both the outboardlongitudinal car and the inboard longitudinal car at the same time. Toachieve a pitch forward, the relay 176 closes a pair of normally opencontacts 176b and 176c for energizing the solenoids l50h associated withthe control valves 150, which causes the forward sections to be loweredon both the outboard car and the inboard car at the same time.

To achieve lateral positioning of the vessel module either to thestarboard side or to the port side, two relays I78 and 180 arerespectively energized by closing one of the LAT STBD push-buttonswitches or one of the LAT PORT switches. The normally closed contacts1800 in series with the relay 178, and the normally closed contacts 178ain series with the relay 180 provide an interlock to prevent both relaysfrom being en ergized at the same time.

To achieve lateral movement to starboard, the relay 178 closes normallyopen contacts 178b, 178C, 178d and 1780. Closing of the contacts 178bcompletes the circuit through the solenoid 152a associated with thecontrol valve 152, to operate the forward lateral hydraulic cylinders920 on the outboard car in the starboard direction. Similarly closing ofthe contacts 178(- operates the corresponding valve 152 in the inboardcar. Closing the contacts 178d and 178s closes the control valves 158 inthe outboard car and the inboard car to effect the starboard movement ofthe aft lateral hydraulic cylinders 92b on both cars simultaneously.

Similarly the normally open contacts 1801), 180e, 180a. and 1806 areclosed by the relay 180 to operate the control valves 152 and 158 inboth the inboard and outboard cars simultaneously, providing lateralmovement to the port side by the platens of both cars.

Finally the yaw control of the module in either the clockwise (CW) orcounter-clockwise (CCW) direction is controlled respectively by a relay182 and a relay 184 (See FIG. 11). The relay 182 is energized byactuating either the remote or local CW push-button switch. energizingthe relay 182 through a pair of normally closed contacts 184a. Similarlythe relay 184 is energized by operating either one of the CCW pushbuttonswitches through the normally closed contacts 182a. Again the contacts182a and 184a provide an interlock preventing both relays from beingenergized at the same time.

Referring to FIG. 13, with the relay 182 closed to provide a clockwiseyaw. normally open contacts 182!) are closed. energizing the solenoid154a and operating the control valve 154 to provide a forward car driveof the outboard longitudinal car. At the same time normally opencontacts 182C are closed completing a circuit energizing the solenoid154b associated with the control valve 154 on the inboard car so as tocause the inboard car to drive in an aft direction. Also the relay 182closes normally open contacts 182d, energizing the solenoid 152aassociated with the control valve 152 and causing the outboard carforward lateral control to move the forward end of the platen in astarboard direction. Normally open contacts 182f at the same timeenergize the solenoid l58b of the control valve 158 on the outboard carto cause the aft lateral control to move in the port direction. Thus theplaten on the outboard car is caused to pivot in a clockwise direction.At the same time normally open contacts 182e and 182g operate thecontrol valves 152 and 158 on the inboard car to move the forward end ofthe platen in a lateral direction to the starboard side and the aft endto the port side. thereby rotating the platen on the inboard car also ina clockwise direction.

The relay 184, when energized, produces at counterclockwise yaw of themodule by means of normally open contacts 184b and 1846 which causesolenoids 154b in the outboard car and 154a in the inboard car to beenergized. This causes the outboard car to move aft and the inboard carto move forward. At the same time contacts 184a and l84f operatesolenoids 1521) and 158a on the outboard car to produce counterclockwiserotation of the outboard car platen. The contacts 184e and 184g at thesame time complete a circuit to solenoids l52b and 158a of the inboardcar to produce counter-clockwise rotation of the inboard car platen.

The lift leveler control portion of the circuit of H6. 11 includes arelay 186 operated by a pair of STOP switches having normally closedcontacts in series with normally open contacts 186a operated by therelay 186. A pair of LEVEL switches have normally open contactsconnected in parallel with the contacts 1860 so that operation of eitherLEVEL switch activates relay 186, closing contacts 1860. Operatingeither STOP switch breaks the circuit, releasing relay 186. The relay186 operates normally open contacts 186!) to complete a circuit throughsolenoid b to operate valve 155 in both the inboard and outboard cars 66and 68.

Each of the relays 162 184 of the relay control circuit of FIG. 11operates normally open contacts, as shown in FIG. 12, for completing acircuit through the bypass valves 148a and 148b associated with thepumps 140a and 14% respectively. These normally open contacts areindicated at 162' through 186' in the outboard car and 162" through 186"in the inboard car. It should be noted that the inboard car does notinclude contacts for the roll control relays and 172, since only theoutboard car platen is raised and lowered dur-. ing the roll operation.Thus it will be seen that when many of the control relays are actuated.the bypass valves are closed to provide hydraulic fluid from the pumpsto the various control cylinders and drive motors.

Since the forward and aft drive of the two longitudinal cars 66 and 68results in the movement of a considerable mass, it is desirable thatthere be a braking action for decelerating the mass when the STOPbuttons are actuated. This is accomplished hydraulically by means of apressure relief valve arrangement as shown in FIG. 10. The relief valve,indicated at 190, is arranged to be normally closed to the flow ofhydraulic fluid but is forced open when the pressure of the hydraulicfluid exceeds some predetermined limit, for example, 3,000 psi. Thevalve 190 is connected across the drive motors 100 by means of fourcheck valves 192,

1. A car for use in the transport of prefabricated hull modules duringthe construction of seagoing ships within a construction dock whichcomprises: a. a chassis; b. a multiplicity of associated pairs of axlemounted rail engaging wheels, each pair of wheels coupled in rotationalrelationship to a pair of oppositely spaced frames, each pair of saidframes connected by torsion means to one another and to said chassis inpivotal relationship at one end thereof and each frame of a pair coupledat the opposed end thereof to said chassis by control means, saidcontrol means adapted to pivot said frames about the axis of rotation ofassociated pairs of wheels to permit controlled raising and lowering ofsaid chassis relative to the wheels to a selected position while capableof maintaining said chassis essentially level in a transverse direction,at least a portion of the multiplicity of the pairs of axle mountedwheels being provided with means to propel said car in a forward andreverse direction; and c. means associated with said chassis to supportsaid modules.
 2. A car as claimed in claim 1 in which the meansassociated with said chassis to support said modules comprises a modulesupporting platen spaced from said chassis by a plurality of slidebearing surfaces and connected to the fore and aft portions of saidchassis by means adapted to move said platen in a horizontal planelaterally relative to said chassis and rotationally relative to saidchassis without raising or lowering of said platen relative to saidchassis.
 3. A car as claimed in claim 2 in which the multiplicity ofassociated frame mounted pairs of axle mounted rail engaging wheels aredivided into forward and aft groups, each group interacting inconjunction through the control means provided for each associated pairof wheels to provide a selected degree of pitch to the car.
 4. A car asclaimed in claim 2 in which the control means to pivot said frames aboutthe axis of said associated pairs of axle mounted wheels and the meansto propel said car are hydraulically actuated.
 5. A car as claimed inclaim 4 in which the means adapted to move said platen laterally androtationally relative to said chassis is hydraulically activated.
 6. Acar as claimed in claim 1 in which the multiplicity of associated framemounted pairs of axle mounted rail engaging wheels are divided intoforward and aft groups, each group interacting in conjunction throughthe control means provided for each associated pair of wheels to providea selected degree of pitch to the car.
 7. A car as claimed in claim 6 inwhich the forward and aft groups of wheels are separately activated byan interconnected hydraulic system to provide pitch to the car and withan hydraulically operated drive system associated with a portion of theaxle mounted wheels of each group.
 8. A car as claimed in claim 1 inwhich the control means to pivot said frames about the axis of saidassociated pairs of axle mounted wheels and the means to propel said carare hydraulically actuated.
 9. A method for transporting hull modulesfrom dockside to a seagoing ship under construction which comprises: a.depositing the module onto a supporting cradle and rotating said cradleinto a construction dock to position the module above a set oftransverse tracks in an upright position; b. moving a set of railmounted transverse cars having a module supporting chassis and at leastthe operational functional modes of forward, reverse, and lift anddescent of the chassis relative to the tracks under the module, thechassis of the set of cars being in a descent mode when moved under themodule; c. lifting the module from the cradle by raising the chassis ofsaid transverse cars and moving the module transversely across the dock;d. depositing the module onto preset supports by lowering the chassis ofthe set of transverse cars and moving the transverse cars from under themodule; e. moving under the module a set of rail mounted transport carshaving module supporting chassis attended by at least one power-controlcar for said transport cars, the set of transport cars, as controlled bythe power-control car, having the functional modes of forward, reverse,and with respect to the chassis thereof lift, descent, pitch, roll andyaw, the chassis of the transport cars being in the descent mode whenbrought under the module; f. lifting the module from the supports byraising the chassis of the transport cars and moving the modulesupporting transport cars along a longitudinal set of rails; g.positioning the module against a preassembled existing portion of theship hull by manipulation of the operational modes of the transport carsfor securement to the existing portion of the hull.
 10. A method fortransporting hull modules from dockside to a seagoing ship underconstruction which comprises: a. depositing the module onto a supportingcradle and rotating said cradle into a construction dock to position themodule above a set of transverse tracks in an upright position; b.moving a set of rail mounted transverse cars having a module supportingchassis and at least the operational functional modes of forward,reverse, and lift and descent of the chassis relative to the tracksunder the module, the chassis of the set of cars being in a descent modewhen moved under the module; c. lifting the module from the cradle byraising the chassis of said transverse cars and moving the moduletransversely across the dock; d. depositing the module onto presetsupports by lowering the chassis of the set of transverse cars andmoving the transverse cars from under the module; e. moving under themodule a set of rail mounted transport cars having module supportingchassis attended by at least one power-control car for said transportcars, the set of transport cars, as controlled by the power-control car,having the functional modes of forward, reverse, and with respect to thechassis thereof lift, descent, pitch, roll and yaw, the chassis of thetransport cars being in the descent mode when moved under the module; f.lifting the module from the supports by raising the chassis of thetransport cars and moving the module supporting transport cars alonglongitudinal rails and depositing the module onto another set ofsupports associated with a second set of transverse rails by loweringthe chassis of the transport cars; g. moving the set of transport carsfrom under the deposited module; h. moving a set of transverse cars withthe chassis thereof in a descent mode under the module and lifting themodule from the supports by raising the chassis of transverse cars andmoving the module supporting transverse cars to return the moduletransversely across the dock; i. depositing the module onto another setof supports by lowering the chassis of the transverse cars and movingthe transverse cars from under the deposited module; j. moving a set oftransport cars with at least one attendant power-control car saidtransport cars as controlled by the power-control car having thefunctional modes defined in under the module with the chassis of thetransport cars being in the descent mode when moved under the module; k.lifting the module from the supports by raising the chassis of thetransport cars and moving the module supporting transport cars along alongitudinal set of rails; l. positioning the module against apreassembled existing portion of the ship hull by manipulation of theoperational modes of the transport cars for securement to the existingportion of the hull.
 11. A system for transporting hull modules in anupright position within a construction dock which comprises: a. at leastone set of transverse rail mounted transverse cars having at least theoperational modes of forward, reverse, and with respect to the chassisof said transverse cars the modes of lift and descent, said transversecars adapted to traverse the interior of a construction dock andtransport a module on associated sets of transverse rails containedwithin the dock; b. at least one set of longitudinal rail mountedtransport cars having at least one attending power-control car, thetransport cars adapted to move longitudinally on associated pairs ofassociated sets of longitudinal rails contained within the constructiondock along the port and starboard sides of the interior of theconstruction dock, said power-control car having the capacities offorward and reverse modes of operation as well as with respect to amodule supported by the chassis of the set of transport cars ofimparting forward and reverse modes of operation through said transportcars and through the chassis of said transport cars, the modes of lift,descent, pitch, roll, lateral movement and yaw, the modes of lateralmovement and yaw being impartable without raising or lowering of saidmodule.
 12. A system as claimed in claim 11 in combination with a rotarypositioning fixture associated with a set of transverse rails employedby the transverse cars which comprises a framework contained within thedock and having thereon a rotatable el-shaped cradle adapted to accept ahull module in a side position and by rotation of the cradle deposit themodule within the dock in an upright position at a predeterminedelevation for reception by a set of transverse cars.
 13. Ship buildingapparatus for constructing a hull from prefabricated modules within aconstruction dock comprising first and second rail mounted movablesupport platforms each platform comprising a chassis and a platenseparated from the chassis by slide bearing surfaces and a multiplicityof axle connected associated wheel pairs, each wheel pair coupled inrotational relationship to a pair of oppositely spaced frames, each pairof said frames connected by torsion means to one another and to saidchassis in pivotal relationship at one end thereof and each frame of apair coupled at the opposed end thereof to said chassis by controlmeans, said platforms supporting one of said modules; means for movingsaid platforms along parallel paths extending lengthwise of the hullbeing constructed for positioning the module longitudinally; saidcontrol means for controllably raising or lowering one platform relativeto the other for rotating the module about a horizontal longitudinalaxis to impart roll, and for tilting both platforms simultaneously in afore or aft direction for rotating the module about a horizontal lateralaxis to impart pitch; and means for transversely moving the platens ofeach platform relative to the chassis without raising and lowering theplatens of each platform relative to the chassis and for rotating theplatens of both platforms in a horizontal plane and in a clockwise orcounter-clockwise direction and simultaneously moving one platformlongitudinally relative to the other for rotating the module about avertical axis without raising and lowering of the module to impart yaw.14. Apparatus as defined in claim 13 in which said control meanscomprise first and second groups of hydraulic lift cylinders pivotablyinterconnecting the spaced frames to the chassis, the groups of liftcylinders being positioned adjacent opposite ends of the chassis, andmeans for imparting transverse movement and yaw comprising first andsecond groups of hydraulic lateral cylinders interconnecting the chassisand the platen, the groups of lateral cylinders being positionedadjacent opposite ends of the chassis.
 15. Apparatus for positioning aload comprising a car movable along parallel rails, the car including amultiplicity of rotatable axle connected rail engaging wheel pairs and achassis; each wheel pair rotatably coupled to a pair of oppositelyspaced frames, each pair of said frames connected by torsion bars and tosaid chassis in pivotal relation at one end thereof and at the opposedend thereof to said chassis through a pair of pivotable hydrauliccylinders, the hydraulic cylinders of the wheel pairs divided into firstand second groups of hydraulic cylinders for controllably raising,lowering, rolling and pitching the chassis relative to the rails, andhydraulic drive means for driving the car in either direction along therails; the load being applied to the chassis, the first group ofhydraulic cylinders being positioned adjacent the front end of the carand the second group of hydraulic cylinders being positioned adjacentthe back end of the car, all the cylinders in a group beinginterconnected hydraulically to each other so that hydraulic fluidpressure is equalized in all the cylinders of a group, the cylinders ofeach pair being positioned adjacent opposite sides of the car, meanscontrolling the flow of hydraulic fluid under pressure separately to thetwo groups of cylinders; said torsion bars resisting unequal verticalmovement of the opposite sides of the chassis relative to the wheels.16. Apparatus as defined in claim 15 further comprising a separatehydraulic fluid source for each group of cylinders, means for limitingthe output pressure of each of said sources to a level insufficient tolift the chassis when subject to the full weight of the load, and meansfor selectively connecting and disconnecting said pressure limitingmeans and said sources.
 17. A car for use in the transport ofprefabricated hull modules during the construction of seagoing shipswithin a construction dock which comprises: a. a chassis; b. meansassociated with said chassis to support said modules comprising a modulesupporting platen spaced from said chassis by a plurality of slidebearing surfaces and connected to the fore and aft portion of saidchassis by means adapted to move said platen in a horizontal planelaterally to said chassis and rotationally relative to said chassiswithout raising or lowering of said platen relative to said chassis; c.a multiplicity of associated pairs of axle mounted rail engaging wheels,each pair of wheels coupled in rotational relationship to a pair ofoppositely spaced frames, each pair of said frames connected by torsionmeans to one another and to said chassis in pivotal relationship at oneend thereof and each frame of a pair coupled at the opposed end thereofto said chassis by control means, said control means adapted to pivotsaid frames about the axis of rotation of associated pairs of wheels topermit controlled raising and lowering of said chassis relative to thewheels to a selected position while capable of maintaining said chassisessentially level in a transverse direction, at least a portion of themultiplicity of the pairs of axle mounted wheels being provided withmeans to propel said car in a forward and reverse direction; and d.means associated with said chassis to support said modules.
 18. A car asclaimed in claim 17 in which the multiplicity of associated framemounted pairs of axle mounted rail engaging wheels are divided intoforward and aft groups, each group interacting in conjunction throughthe control means provided for each associated pair of wheels to providea selected degree of pitch to the car.
 19. A car as claimed in claim 17in which the control means to pivot said frames about the axis of saidassociated pairs of axle mounted wheels and the means to propel said carare hydraulically actuated.
 20. A car as claimed in claim 17 in whichthe means adapted to move said platen laterally and rotationallyrelative to said chassis is hydraulically actuated.